JP4416378B2

JP4416378B2 - Method for producing irregular shaped granule and irregular shaped aggregate

Info

Publication number: JP4416378B2
Application number: JP2002152281A
Authority: JP
Inventors: 知伸上保; 勝史小野; 浩行二宮; 憲史永田
Original assignee: Taiheiyo Cement Corp
Current assignee: Taiheiyo Cement Corp
Priority date: 2002-05-27
Filing date: 2002-05-27
Publication date: 2010-02-17
Anticipated expiration: 2022-05-27
Also published as: JP2003342048A

Description

【０００１】
【発明の属する技術分野】
本発明は、異形造粒物及び異形骨材の製造方法に関し、特に、石炭灰を主原料とする粉粒体から異形造粒物及び異形骨材を製造する方法に関する。
【０００２】
【従来の技術】
近年、石炭焚き火力発電所から発生する大量の石炭灰の有効活用の一環として、石炭灰を何らかのバインダー成分を用いて成形・固化し、固化物を人工骨材、敷き砂利、埋め戻し材、サンドコンパクション等に利用する研究が数多くなされている。
【０００３】
石炭灰を人工骨材の材料として利用する場合には、石炭灰を主体とする粉体に水を混合してパンペレタイザー等によって造粒し、造粒物を蒸気養生するか、または焼成して人工骨材を製造することが行われている。
【０００４】
しかし、このようにして製造された人工骨材は、球形であるため、転がり易く、ハンドリングが困難であるという問題があった。例えば、ベルトコンベアで輸送するにあたって、特にベルトコンベアが傾斜しているような場合には、ベルトから落下して輸送が困難となったり、保管の際に山積みするにも積み上げるのが困難である等の問題があった。
【０００５】
そこで、球形ではなく異形の骨材を製造する方法について種々研究開発がなされている。例えば、特開平９−２４１０５１号公報に記載の非焼成骨材の製造方法では、石炭灰を主体とする粉体に水を加えて造粒した後、蒸気養生し、その後、骨材を所定の粒径範囲の粒分と、大粒径の粒分とに分離し、大粒径の粒分及び／または所定範囲の粒分の一部を破砕した後、所定の粒径範囲にある骨材を製造する。
【０００６】
また、特開昭５８−１１５０６３号公報に記載の異形軽量骨材の製造方法では、フライアッシュを含む原料に水を加えてパンペレタイザーによって造粒する過程でさらに水を加えることによって異形の生ペレットを成形した後、乾燥・焼結することによって異形軽量骨材を製造する。
【０００７】
さらに、特開昭５８−１１５０６３号公報には、製鉄スラグ、火山礫破砕物等の多孔性無機溶融物を核体とし、これに耐火性材料粉末による被覆層形成材料及び水を加えつつ核体とともに回転攪拌し、その際に約１／２〜数分間ずつ数回回転数を２／３〜１／４に低下させることにより、コンペイ糖状の軽量骨材を製造する方法が開示されている。
【０００８】
【発明が解決しようとする課題】
しかし、上記特開平９−２４１０５１号公報に記載の非焼成骨材の製造方法では、大粒径の粒分及び／または所定範囲の粒分の一部を破砕して骨材を製造しているため、骨材にマイクロクラック等が発生し、所望の強度を得ることができないおそれがある。特に、人工の骨材であっても表面から内部まで均一であるとは言い難く、破砕によって骨材の性状が変化するおそれも十分にある。
【０００９】
また、特開昭５８−１１５０６３号公報に記載の異形軽量骨材の製造方法では、パンペレタイザーによって異形の生ペレットを成形しているが、パンペレタイザーの操作には特異な技術を要し、球状の造粒物を得る場合であっても相当の熟練度を必要とするため、異形の造粒物を効率よく製造するのは困難で、特に大量生産を行うのは容易ではないという問題がある。
【００１０】
さらに、特開昭５８−１１５０６３号公報に記載のコンペイ糖状軽量骨材の製造方法では、ドラム型のペレタイザーを使用しているが、造粒時間、造粒効率を考慮すると、やはり大量生産を行うのは容易ではないという問題があった。
【００１１】
そこで、本発明は、上記従来の技術における問題点に鑑みてなされたものであって、所望の強度を得ることができ、高効率で大量生産も可能な異形造粒物及び異形骨材を製造する方法を提供することを目的とする。
【００１２】
【課題を解決するための手段】
上記目的を達成するため、請求項１に記載の発明は、非球状の造粒物を生成する異形造粒物の製造方法であって、石炭灰を主体とし、かつ、石炭灰１００重量部に対する粘結性材料の配合割合を１重量部以上、３重量部未満とした粉粒体を、逆円錐台状攪拌混合装置を用いて造粒することを特徴とする。
【００１３】
そして、請求項１に記載の発明によれば、石炭灰を主原料とする粉粒体から異形造粒物を製造するにあたって、石炭灰１００重量部に対する粘結性材料の配合割合を１重量部以上、３重量部未満とし、逆円錐台状攪拌混合装置を用いて造粒するため、操作が容易で、歩留まりがよく、かつ、短い造粒時間で、効率よく異形造粒物を製造することができる。逆円錐台状攪拌混合装置を用いると、粉粒体同士に鉛直方向の適当な圧力が加わり、造粒物に対する成形圧を生じさせることができるため、粉体圧が局所的に高まって造粒物を潰すおそれを回避することができる。粘結性材料を３重量部以上配合した場合には、造粒物が球状になり易く、好ましくない。
【００１４】
請求項２に記載の発明は、請求項１に記載の異形造粒物の製造方法において、前記逆円錐台状攪拌混合装置の内壁を錐面の一部とする円錐の半頂角が３５°以下であることを特徴とする。
【００１５】
請求項２に記載の発明によれば、内壁を錐面の一部とする円錐の半頂角を３５°以下としたため、攪拌羽根の外縁の直径と混合槽の最大内径との比が小さくなり、混合槽の内壁と攪拌羽根との距離が狭まり、粉体同士の接触頻度が高まり、かつ、混合槽内壁と攪拌羽根との間の粉体圧が上昇して結合エネルギーが増大する。これによって、粉粒体の造粒物を得るための攪拌混合時間を大幅に短縮することができる。ここで、円錐の半頂角が３５°より大きいと、攪拌羽根と混合槽の内壁との距離が広がり、その間の粉体圧が減少して結合エネルギーが十分に得られなくなるので好ましくない。
【００１６】
請求項３に記載の発明は、請求項１または２に記載の異形造粒物の製造方法において、前記逆円錐台状攪拌混合装置の混合槽の中央に、鉛直方向に延設された回転軸に一または複数の螺旋が設けられ、粉粒体を上方に掻き揚げる方向に回転することを特徴とする。これによって、粉粒体は、螺旋上を上方向へ転がり上がるような成形圧を受け、強い結合エネルギーを得る。この効果を得るためには、短い螺旋に分割された多段型螺旋羽根よりも、連続螺旋であることがより好ましい。
【００１７】
請求項４に記載の発明は、請求項３に記載の粉粒体の混合造粒装置において、前記螺旋の径が上方ほど大きくなることを特徴とする。これによって、混合槽の内壁と攪拌羽根との距離が上方においても狭まり、高い粉体圧を得ることができる。
【００１８】
請求項５に記載の発明は、請求項１乃至４のいずれかに記載の異形造粒物の製造方法において、前記石炭灰のブレーン比表面積α（ｃｍ²／ｇ）と、造粒時に添加する水分の外割添加率β（重量％）との関係を、１２０≦α／β≦１４０としたことを特徴とする。α／βが１４０を超えると、混合物がまだ乾燥状態に近く、造粒することができない。また、α／βが１２０未満の場合には、造粒物が球状になり易く、好ましくない。
【００１９】
請求項６に記載の発明は、異形骨材の製造方法であって、請求項１乃至５のいずれかに記載の方法で製造した異形造粒物を蒸気養生により硬化させることを特徴とする。これによって、非焼成の異形骨材を得ることができる。
【００２０】
請求項７に記載の発明は、異形骨材の製造方法であって、請求項１乃至５のいずれかに記載の方法で製造した異形造粒物を焼結することを特徴とする。これによって、焼成異形骨材を得ることができる。
【００２１】
請求項８に記載の発明は、異形造粒物であって、石炭灰を主体とし、かつ、石炭灰１００重量部に対する粘結性材料の配合割合を１重量部以上、３重量部未満とした粉粒体の造粒物であって、かつ、個々の造粒物の最短径に対する最長径の比が１．２以上、３以下であり、造粒物のフロー値が２５ｃｍ以上であり、さらに造粒物のゴム平板上の転がり傾斜角が１５°以上であることを特徴とする。これによって、適度に凹凸があって、角がなく、高い流動性を保持しながら、ハンドリング性のよい造粒物、ひいては、ハンドリング性のよい骨材を得ることができる。
【００２２】
尚、造粒物のフロー値とは、径７６ｍｍ、高さ９０ｍｍの円筒に、１０〜１５ｍｍに粒度調整した造粒物を、定規を当てて円筒上部すりきり位置まで投入し、円筒を真上に引き揚げると、造粒物が略々円形に拡がるので、最長径と、これに直交する径の長さの平均を測定し、５回測定した平均値である。また、ゴム平板上の転がり傾斜角とは、ゴム平板上に造粒物を置き、ゴム平板を傾けて造粒物が転がり落ちるときの傾斜角であって、任意に抽出した造粒物１００個について測定を行い、その平均値を用いる。
【００２３】
【発明の実施の形態】
次に、本発明にかかる異形造粒物及び異形骨材の製造方法の実施の形態について図面を参照しながら説明する。
【００２４】
本発明では、石炭焚き火力発電所から排出される石炭灰を主原料とし、かつ、石炭灰１００重量部に対する粘結性材料の配合割合を１重量部以上、３重量部未満とする。これによって、造粒物を球形ではなく、好ましい異形にすることができる。また、造粒物に十分な強度を付与するために水硬性材料を配合することが好ましく、さらに、硬化促進剤を添加してもよい。
【００２５】
ここで、粘結性材料とは、カオリンやベントナイトといった粘土鉱物性無機物質やパルプ製造時に廃液中に含まれるリグニン等である。また、水硬性材料とは、各種セメントや、各種石膏、さらには、メチルセルロース等の水溶性高分子等である。硬化促進剤とは、造粒物の磨り減り抵抗性や落下強度を増大させるために添加されるものであって、水ガラス、アルミン酸ソーダ等の急硬材や、いわゆるトンネル吹き付けに利用される急結材等をいう。十分な強度を得るためには、石炭灰１００重量部に対し、水硬性材料５〜２０重量部を配合することが好ましい。さらに、硬化促進剤１〜５重量部を添加することが好ましい。
【００２６】
また、異形の程度は、個々の造粒物の最短径に対する最長径の比が１．２以上、３以下であり、かつ、造粒物のフロー値が２５ｃｍ以上であり、さらに造粒物のゴム平板上の転がり傾斜角が１５°以上とすることが好ましい。造粒物のフロー値が２５ｃｍ以上であれば、例えば、この造粒物から製造した焼結骨材をコンクリート用骨材として用いた時に、ポンプ圧送に十分な流動性が得られる。さらに、ゴム平板上の転がり傾斜角が１５°以上であれば、例えば、傾斜したベルトコンベアで輸送する場合でも、造粒物がベルトから落下して輸送が困難となるようなこともなく、保管の際に山積みする際等にもハンドリングが容易になる。
【００２７】
次に、本発明にかかる異形造粒物の製造方法に用いる逆円錐台状攪拌混合装置の一実施例について図１を参照しながら説明する。
【００２８】
この逆円錐台状攪拌混合装置１は、バッチ式の攪拌混合装置であって、大きく分けて、混合槽２と、攪拌羽根３と、掻取羽根４（４Ａ、４Ｂ、４Ｃ）とで構成される。
【００２９】
混合槽２は、水平かつ円形の底面２ａと曲面状内壁２ｂとで囲繞された逆円錐台状の内部空間２ｃと、内部空間２ｃの上方に円筒状空間２ｄを有し、混合槽２内に、攪拌羽根３と掻取羽根４とが配置される。混合槽２の上部には原料投入口６が設けられる。底面２ａは、横にスライドすることにより処理物排出口７が開口する。
【００３０】
攪拌羽根３は、螺旋状に形成され、混合槽２の中心部において鉛直方向に延設された回転軸５に一体に設けられる。攪拌羽根３は、連続螺旋であることが好ましく、また、上方ほど径が大きいことが好ましい。攪拌羽根３の回転速度は、図示しない制御装置によって調整することができる。
【００３１】
掻取羽根４（４Ａ、４Ｂ、４Ｃ）は、アーム８を介して図示しない回転軸によって、各々混合槽２の曲面状内壁２ｂに沿って回転し、曲面状内壁２ｂへの付着物を掻き取る。この掻取羽根４の回転速度も、図示しない制御装置によって調整することができる。掻取羽根４は、攪拌羽根３とは反対方向に回転する。
【００３２】
次に、上記構成を有する逆円錐台状攪拌混合装置１の各部の寸法関係について説明する。
【００３３】
混合槽２の内部空間２ｃは、この混合槽２の底面２ａを共有し、曲面状内壁２ｂを錐面の一部とする円錐を考えた場合、その半頂角θが３５°以下に設定される。また、攪拌羽根３の最大径ｂは、混合槽２の底面内径ａの７０％以上とする。さらに、攪拌羽根３の高さｅは、混合槽２の逆円錐台状内部空間２ｃの高さｄの７０％以上とする。掻取羽根４と、混合槽２の曲面状内壁母線長さｆとの接触比率を８０％以上とする。
【００３４】
次に、本発明にかかる逆円錐台状攪拌混合装置の試験例について説明する。尚、以下の実施例では、上記構成を有する逆円錐台状攪拌混合装置１（容量５０リットル、θ＝３０°）を用いて造粒試験を行った。
【００３５】
試験結果を表１に示す。尚、試験にあたって、粘結性材料にベントナイトを使用した。また、石炭灰１００重量部に対し、水硬性材料としてセメントを１５重量部、硬化促進剤として水ガラスを１重量部配合した。
【００３６】
【表１】

【００３７】
表１に示すように、石炭灰１００重量部に対する粘結性材料の配合割合を１重量部１以上、３重量部未満とするとともに、石炭灰のブレーン比表面積α（ｃｍ²／ｇ）と、造粒時に添加する水分の外割添加率β（重量％）との関係を、１２０≦α／β≦１４０とすることにより、個々の造粒物の最短径に対する最長径の比が１．２以上、３以下で、フロー値が２５ｃｍ以上であり、ゴム平板上の転がり傾斜角が１５°以上の所望の異形造粒物を得ることができることが判る。
【００３８】
そして、上記のようにして製造された異形造粒物を蒸気養生により硬化させて非焼成の異形骨材を、また、焼結することによって焼成異形骨材を製造することができる。
【００３９】
尚、比較例１０として、砕石との比較も行った。砕石は、茨城県岩瀬産硬質砂岩砕石の粒径１０〜１５ｍｍのものを用いた。
【００４０】
【発明の効果】
以上説明したように、本発明にかかる異形造粒物及び異形骨材製造方法によれば、所望の強度を得ることができ、高効率で大量生産も可能な異形造粒物及び異形骨材を製造することができる。製造された異形造粒物は、高い流動性を保持しながら、転がりにくく、山積も可能であり、ハンドリング性に優れる。
【図面の簡単な説明】
【図１】本発明にかかる異形造粒物製造方法で用いる逆円錐台状攪拌混合装置の一実施例を示す断面図である。
【符号の説明】
１逆円錐台状攪拌混合装置
２混合槽
２ａ底面
２ｂ曲面状内壁
２ｃ逆円錐台状内部空間
２ｄ円筒状空間
３攪拌羽根
４掻取羽根
５回転軸
６原料投入口
７処理物排出口
８アーム
ａ混合槽円形底面直径
ｂ攪拌羽根の直径
ｃ混合槽の逆円錐台状内部空間最大内径
ｄ逆円錐台状内部空間の高さ
ｅ攪拌羽根高さ
ｆ曲面状内壁母線長さ
θ 半頂角[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing deformed granules and deformed aggregates, and more particularly, to a method for producing deformed granules and deformed aggregates from a powder granule mainly composed of coal ash.
[0002]
[Prior art]
In recent years, as part of effective utilization of a large amount of coal ash generated from coal-fired thermal power plants, coal ash is formed and solidified using some binder component, and the solidified material is artificial aggregate, shingle gravel, backfill material, sand Many studies have been made for compaction.
[0003]
When coal ash is used as a material for artificial aggregate, water is mixed with coal ash-based powder and granulated with a pan pelletizer, etc., and the granulated product is steam-cured or calcined. Artificial aggregates are manufactured.
[0004]
However, since the artificial bone manufactured in this way is spherical, there is a problem that it is easy to roll and difficult to handle. For example, when transporting on a belt conveyor, especially when the belt conveyor is inclined, it is difficult to transport by falling from the belt, or it is difficult to stack even when piled up during storage. There was a problem.
[0005]
Therefore, various researches and developments have been made on methods for producing irregular shaped aggregates instead of spherical shapes. For example, in the method for producing a non-fired aggregate described in JP-A-9-241551, water is added to a powder mainly composed of coal ash, granulated, and then steam-cured, and then the aggregate is subjected to a predetermined process. Aggregates in a predetermined particle size range after being separated into a large particle size particle portion and a large particle size particle portion and / or part of the large particle size particle portion and / or a predetermined particle size range Manufacturing.
[0006]
Further, in the method for producing a deformed lightweight aggregate described in JP-A-58-115063, a deformed raw pellet is obtained by adding water to a raw material containing fly ash and further adding water during granulation by a pan pelletizer. After molding, the deformed lightweight aggregate is manufactured by drying and sintering.
[0007]
Furthermore, in Japanese Patent Laid-Open No. 58-115063, a core is made of a porous inorganic melt such as iron slag, crushed gravel, etc., and a coating layer forming material made of a refractory material powder and water are added thereto. And a method of producing a lightweight sugar-like aggregate by reducing the number of rotations to 2/3 to ¼ several times for about ½ to several minutes each time. .
[0008]
[Problems to be solved by the invention]
However, in the method for producing a non-fired aggregate described in JP-A-9-241551, the aggregate is produced by crushing a large particle size and / or a part of a predetermined range. For this reason, microcracks or the like are generated in the aggregate, and the desired strength may not be obtained. In particular, it is difficult to say that even an artificial aggregate is uniform from the surface to the inside, and there is a possibility that the properties of the aggregate will change due to crushing.
[0009]
Further, in the method for producing a deformed lightweight aggregate described in Japanese Patent Application Laid-Open No. 58-115063, a deformed raw pellet is formed by a pan pelletizer. However, it is difficult to efficiently produce irregularly shaped granules, and it is not easy to carry out mass production in particular. .
[0010]
Furthermore, in the manufacturing method of a lightweight sugar aggregate as disclosed in JP-A-58-115063, a drum-type pelletizer is used. However, considering granulation time and granulation efficiency, mass production is still necessary. There was a problem that it was not easy to do.
[0011]
Therefore, the present invention has been made in view of the problems in the above-described conventional technology, and can produce deformed granules and deformed aggregates that can obtain a desired strength and can be mass-produced with high efficiency. It aims to provide a way to do.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 is a method for producing a deformed granulated product that produces a non-spherical granulated product, comprising coal ash as a main component and 100 parts by weight of coal ash. It is characterized by granulating a granular material in which the compounding ratio of the caking material is 1 part by weight or more and less than 3 parts by weight using an inverted frustoconical stirring and mixing device.
[0013]
And according to invention of Claim 1, in manufacturing a deformed granulated material from the granular material which uses coal ash as a main raw material, the mixture ratio of caking material with respect to 100 weight part of coal ash is 1 weight part. Above, less than 3 parts by weight, and granulated using an inverted frustoconical stirring and mixing device, so that it is easy to operate, has a good yield, and efficiently produces irregular shaped granules in a short granulation time. Can do. When an inverted frustoconical stirring and mixing device is used, an appropriate pressure in the vertical direction is applied between the granulates, and a molding pressure can be generated on the granulated product, so that the powder pressure is locally increased and granulated. The risk of crushing things can be avoided. When 3 parts by weight or more of the caking material is blended, the granulated product tends to be spherical, which is not preferable.
[0014]
According to a second aspect of the present invention, in the method for producing a deformed granule according to the first aspect, a half apex angle of a cone having an inner wall of the inverted frustoconical stirring and mixing device as a part of a cone surface is 35 °. It is characterized by the following.
[0015]
According to the invention described in claim 2, since the half apex angle of the cone having the inner wall as a part of the conical surface is set to 35 ° or less, the ratio between the diameter of the outer edge of the stirring blade and the maximum inner diameter of the mixing vessel is reduced. The distance between the inner wall of the mixing tank and the stirring blade is reduced, the frequency of contact between the powders is increased, and the powder pressure between the inner wall of the mixing tank and the stirring blade is increased to increase the binding energy. Thereby, the stirring and mixing time for obtaining a granulated product of the granular material can be greatly shortened. Here, when the half apex angle of the cone is larger than 35 °, the distance between the stirring blade and the inner wall of the mixing vessel is widened, and the powder pressure therebetween is reduced, so that the binding energy cannot be obtained sufficiently.
[0016]
A third aspect of the present invention is the method for producing a deformed granulated product according to the first or second aspect, wherein the rotary shaft extends in the vertical direction at the center of the mixing tank of the inverted frustoconical stirring and mixing device. One or a plurality of spirals are provided, and the powder body is rotated in the direction of lifting up the powder. As a result, the granular material receives a molding pressure that rolls upward on the spiral, and obtains strong binding energy. In order to obtain this effect, a continuous spiral is more preferable than a multi-stage spiral blade divided into short spirals.
[0017]
According to a fourth aspect of the present invention, in the powder granule mixing and granulating apparatus according to the third aspect of the present invention, the spiral diameter increases toward the top. Thereby, the distance between the inner wall of the mixing tank and the stirring blade is narrowed upward, and a high powder pressure can be obtained.
[0018]
A fifth aspect of the present invention is the method for producing a deformed granulated product according to any one of the first to fourth aspects, wherein a specific surface area α (cm ² / g) of the coal ash is added during granulation. It is characterized in that the relationship with the external rate of addition of water β (wt%) is 120 ≦ α / β ≦ 140. When α / β exceeds 140, the mixture is still in a dry state and cannot be granulated. Moreover, when α / β is less than 120, the granulated product tends to be spherical, which is not preferable.
[0019]
The invention described in claim 6 is a method for producing a deformed aggregate, wherein the deformed granulated material manufactured by the method according to any one of claims 1 to 5 is cured by steam curing. Thereby, a non-baked deformed aggregate can be obtained.
[0020]
The invention described in claim 7 is a method for producing a deformed aggregate, wherein the deformed granulated material manufactured by the method according to any one of claims 1 to 5 is sintered. Thereby, a fired deformed aggregate can be obtained.
[0021]
The invention according to claim 8 is a deformed granulated product, mainly composed of coal ash, and the blending ratio of the caking material to 100 parts by weight of coal ash is 1 part by weight or more and less than 3 parts by weight. It is a granulated product of granules, and the ratio of the longest diameter to the shortest diameter of each granulated product is 1.2 or more and 3 or less, and the flow value of the granulated product is 25 cm or more, The rolling inclination angle on the rubber flat plate of the granulated product is 15 ° or more. As a result, it is possible to obtain a granulated product having good handleability, and thus an aggregate having good handleability, while having moderate irregularities, no corners, and high fluidity.
[0022]
In addition, the flow value of the granulated product is a cylinder with a diameter of 76 mm and a height of 90 mm. When pulled up, the granulated product expands in a substantially circular shape. Therefore, the average of the longest diameter and the length of the diameter perpendicular to the longest diameter is measured and is an average value measured five times. Further, the rolling inclination angle on the rubber flat plate is an inclination angle when the granule is placed on the rubber flat plate and the rubber flat plate is inclined to roll off the granulated product. Is measured and the average value is used.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of a method for producing deformed granules and deformed aggregates according to the present invention will be described with reference to the drawings.
[0024]
In the present invention, coal ash discharged from a coal-fired thermal power plant is used as a main raw material, and the blending ratio of the caking material to 100 parts by weight of coal ash is 1 part by weight or more and less than 3 parts by weight. As a result, the granulated product can be made into a preferred shape, not a spherical shape. Moreover, in order to give sufficient intensity | strength to a granulated material, it is preferable to mix | blend a hydraulic material, Furthermore, you may add a hardening accelerator.
[0025]
Here, the caking material is a clay mineral inorganic material such as kaolin or bentonite, or lignin contained in waste liquid during pulp production. The hydraulic material includes various cements, various gypsums, and water-soluble polymers such as methylcellulose. The hardening accelerator is added to increase the abrasion resistance and drop strength of the granulated product, and is used for rapid hardening materials such as water glass and sodium aluminate, and so-called tunnel spraying. It means quick setting materials. In order to obtain sufficient strength, 5 to 20 parts by weight of a hydraulic material is preferably blended with 100 parts by weight of coal ash. Furthermore, it is preferable to add 1 to 5 parts by weight of a curing accelerator.
[0026]
In addition, the degree of deformation is such that the ratio of the longest diameter to the shortest diameter of each granulated product is 1.2 or more and 3 or less, and the flow value of the granulated product is 25 cm or more. The rolling inclination angle on the rubber flat plate is preferably 15 ° or more. If the flow value of the granulated product is 25 cm or more, for example, when a sintered aggregate produced from this granulated product is used as an aggregate for concrete, sufficient fluidity for pumping can be obtained. Further, when the rolling inclination angle on the rubber flat plate is 15 ° or more, for example, even when transported by an inclined belt conveyor, the granulated material does not fall from the belt and is difficult to transport, and stored. Handling is also easy when stacking.
[0027]
Next, an example of an inverted frustoconical stirring and mixing apparatus used in the method for producing a deformed granule according to the present invention will be described with reference to FIG.
[0028]
This inverted frustoconical stirring and mixing device 1 is a batch type stirring and mixing device, and is roughly composed of a mixing tank 2, a stirring blade 3, and a scraping blade 4 (4A, 4B, 4C). The
[0029]
The mixing vessel 2 has an inverted frustoconical inner space 2c surrounded by a horizontal and circular bottom surface 2a and a curved inner wall 2b, and a cylindrical space 2d above the inner space 2c. The stirring blade 3 and the scraping blade 4 are arranged. A raw material inlet 6 is provided at the upper part of the mixing tank 2. The processed product discharge port 7 is opened by sliding the bottom surface 2a to the side.
[0030]
The stirring blade 3 is formed in a spiral shape and is provided integrally with a rotating shaft 5 that extends in the vertical direction at the center of the mixing tank 2. The stirring blade 3 is preferably a continuous spiral, and the diameter is preferably larger toward the upper side. The rotational speed of the stirring blade 3 can be adjusted by a control device (not shown).
[0031]
The scraping blades 4 (4A, 4B, 4C) are each rotated along the curved inner wall 2b of the mixing tank 2 by an unillustrated rotating shaft via the arm 8, and scrape off the deposits on the curved inner wall 2b. . The rotational speed of the scraping blade 4 can also be adjusted by a control device (not shown). The scraping blade 4 rotates in the opposite direction to the stirring blade 3.
[0032]
Next, the dimensional relationship of each part of the inverted frustoconical stirring and mixing apparatus 1 having the above configuration will be described.
[0033]
The internal space 2c of the mixing tank 2 shares the bottom surface 2a of the mixing tank 2, and when considering a cone having the curved inner wall 2b as a part of a conical surface, the half apex angle θ is set to 35 ° or less. The The maximum diameter b of the stirring blade 3 is 70% or more of the bottom surface inner diameter a of the mixing tank 2. Furthermore, the height e of the stirring blade 3 is 70% or more of the height d of the inverted frustoconical inner space 2c of the mixing tank 2. The contact ratio between the scraping blades 4 and the curved inner wall bus bar length f of the mixing tank 2 is 80% or more.
[0034]
Next, a test example of the inverted frustoconical stirring and mixing apparatus according to the present invention will be described. In the following examples, a granulation test was performed using the inverted frustoconical stirring and mixing apparatus 1 (capacity 50 liters, θ = 30 °) having the above-described configuration.
[0035]
The test results are shown in Table 1. In the test, bentonite was used as the caking material. Further, 15 parts by weight of cement as a hydraulic material and 1 part by weight of water glass as a curing accelerator were blended with 100 parts by weight of coal ash.
[0036]
[Table 1]

[0037]
As shown in Table 1, the mixing ratio of caking material for coal ash 100 parts by weight 1 part by weight of one or more, as well as less than 3 parts by weight, Blaine specific surface area of the coal ash α and (cm ² / g) The ratio of the longest diameter to the shortest diameter of each granulated product is 1. by setting the relation with the external addition rate β (% by weight) of water added at the time of granulation to 120 ≦ α / β ≦ 140. It can be seen that a desired shaped granulated product having a flow value of 2 cm or more, a flow value of 25 cm or more, and a rolling inclination angle on a rubber flat plate of 15 ° or more can be obtained.
[0038]
Then, the deformed granule produced as described above is cured by steam curing to produce a non-fired deformed aggregate, and a sintered deformed aggregate can be manufactured by sintering.
[0039]
In addition, as Comparative Example 10, comparison with crushed stone was also performed. As the crushed stone, a hard sandstone crushed stone from Iwase, Ibaraki Prefecture having a particle size of 10 to 15 mm was used.
[0040]
【The invention's effect】
As described above, according to the deformed granule and the deformed aggregate manufacturing method according to the present invention, it is possible to obtain the deformed granule and deformed aggregate that can obtain a desired strength and can be mass-produced with high efficiency. Can be manufactured. The produced irregular shaped granule has high fluidity, is difficult to roll, can be piled up, and has excellent handling properties.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of an inverted frustoconical stirring and mixing device used in the method for producing a deformed granule according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Reverse frustoconical stirring mixing apparatus 2 Mixing tank 2a Bottom surface 2b Curved inner wall 2c Reverse frustoconical internal space 2d Cylindrical space 3 Stirring blade 4 Scraping blade 5 Rotating shaft 6 Raw material inlet 7 Processed material outlet 8 Arm a Diameter of mixing tank circular bottom b Diameter of stirring blade c Maximum inner diameter of inverted frustoconical space d of mixing tank Height of reverse frustoconical inner space e Stirring vane height f Curved inner wall bus length θ Half apex angle

Claims

A method for producing a deformed granulated product that produces a non-spherical granulated product, comprising coal ash as a main component, and the blending ratio of the caking material to 100 parts by weight of coal ash is 1 part by weight or more and 3 parts by weight A method for producing a deformed granulated product, comprising granulating a granular material having a particle size of less than one using an inverted frustoconical stirring and mixing device.

The method for producing a deformed granulated product according to claim 1, wherein a half apex angle of a cone having an inner wall of the inverted frustoconical stirring and mixing device as a part of a conical surface is 35 ° or less.

In the center of the mixing tank of the inverted frustoconical stirring and mixing device, one or a plurality of spirals are provided on a rotating shaft extending in the vertical direction, and rotate in a direction in which the powder particles are lifted upward. The manufacturing method of the irregular-shaped granulated material of Claim 1 or 2 to do.

The method for producing a deformed granulated product according to claim 3, wherein the diameter of the spiral increases toward the top.

The relation between the Blaine specific surface area α (cm ² / g) of the coal ash and the external addition rate β (wt%) of water added during granulation is 120 ≦ α / β ≦ 140, The manufacturing method of the irregular shaped granulated material in any one of Claim 1 thru | or 4.

A method for producing a deformed aggregate, comprising curing the deformed granulated product produced by the method according to any one of claims 1 to 5 by steam curing.

A method for producing a deformed aggregate, comprising sintering the deformed granulated product produced by the method according to claim 1.

A granulated product of a granular material mainly composed of coal ash and having a caking material blending ratio of 1 part by weight or more and less than 3 parts by weight with respect to 100 parts by weight of coal ash, and each granulation The ratio of the longest diameter to the shortest diameter of the product is 1.2 or more and 3 or less, the flow value of the granulated product is 25 cm or more, and the rolling inclination angle on the rubber flat plate of the granulated product is 15 ° or more. This is a deformed granulated product.